1. Field of the Invention
The present invention relates to a washing machine, and more particularly, to a drum type washing machine having a water circulation device which pumps wash water contained in a fixed drum to feed the wash water to a rotary drum, so as to enhance the washing effect.
2. Description of the Related Art
Generally, a drum type washing machine is an appliance designed to wash laundry by dropping the laundry from a top to a bottom inside of a rotary drum as the rotary drum is rotated. Such a drum type washing machine includes a fixed drum, a rotary drum and shock absorbing members. The fixed drum is suspended in a box-shaped cabinet which defines an outer appearance of the washing machine, and contains wash water therein. The rotary drum is set in the fixed drum so as to be rotatable in alternating directions. The shock absorbing members support the fixed drum in the box-shaped cabinet.
In conventional drum type washing machines, washing, rinsing, and spin-drying operations are automatically carried out according to a previously input program, while a rotary drum is rotated. In this case, washing courses are classified into a heavy course, a normal course, a wool course, etc., according to a kind and state of laundry to be washed. However, the conventional drum type washing machines are limited in their washing efficiency, because the washing and rinsing operations are achieved only by dropping of the laundry through the rotation of the rotary drum.
To overcome this problem, Korean U.M. Application No. 1997-11762/Laid-Open Publication No. 1998-67224 discloses a wash water circulation device for drum type washing machines. The wash water circulation device forcibly pumps wash water in a fixed drum and sprays the wash water into a rotary drum containing laundry therein.
FIG. 1 shows that the wash water circulation device disclosed above includes a spray nozzle 3 which sprays the wash water pumped from the bottom to the top inside of a tub (the fixed drum) 2 by a drain pump 1, a first solenoid valve 4 which is installed at a position adjacent to the spray nozzle 3 and closes during a drain operation and opens during a washing operation, a water circulation hose 6 having one end connected to the spray nozzle 3 and the other end connected to a T-shaped connector 7 positioned between the drain pump 1 and a drain hose 5, and a second solenoid valve 8 which is installed at an inlet of the drain hose 5 and closes during the washing operation.
The spray nozzle 3 is positioned on top of the tub 2, so as to have the wash water sprayed from the spray nozzle 3 to flow into a drum (the rotary drum) 9 through a plurality of spin-drying perforations 9a formed on a wall of the drum 9. The second solenoid valve 8 prevents the wash water pumped by the drain pump 1 from being drained through the drain hose 5 during the washing operation.
Thus, where the drain pump 1 is activated during the washing operation, which is carried out by rotation of the drum 9, the wash water in the tub 2 is pumped to the top of the tub 2 and then sprayed downward therefrom. That is, the wash water pumped by the drain pump 1 is guided to the spray nozzle 3 through the water circulation hose 6 and then sprayed from the spray nozzle 3 to the drum 9 to flow into the drum 9 through the perforations 9a, so as to improve the washing efficiency and solubility of detergent.
However, since the wash water sprayed from the spray nozzle 3 is first sprayed against an external wall of the drum 9, only a small portion of the sprayed wash water flows into the drum 9 through the perforations 9a. The remaining wash water flows down along the external wall of the drum 9 and is collected in the bottom of the tub 2.
Therefore, although the solubility of the detergent can be improved by circulation of the wash water, the sprayed wash water achieves limited improvement in washing the laundry.